The Relative Strength Index (RSI) is a momentum oscillator used in technical analysis to measure the speed and change of price movements. It ranges from 0 to 100 and is typically used to identify overbought or oversold conditions in a market. An RSI above 70 may indicate that an asset is overbought, while an RSI below 30 suggests it is oversold. Traders often use the RSI in conjunction with other indicators to make informed decisions. It can help identify potential reversal points and trends, making it a valuable tool for those analyzing price charts and market behavior.